<?php
// +----------------------------------------------------------------------
// | 网站名称：
// +----------------------------------------------------------------------
// | 功能介绍：
// +----------------------------------------------------------------------
// | Created by PhpStorm.
// +----------------------------------------------------------------------
// | Time:  2022/3/2
// +----------------------------------------------------------------------
// | Author: 龙志勇 <longzhiyongdxfncel@163.com>
// +----------------------------------------------------------------------
// | Copyright  www.XXXXX.com All rights reserved.
// +----------------------------------------------------------------------
// + ━━━━━━神兽出没━━━━━━
// +
// + 　　 ┏┓     ┏┓
// + 　　┏┛┻━━━━━┛┻┓
// + 　　┃　　　　　 ┃
// +　 　┃　　━　　　┃
// + 　　┃　┳┛　┗┳  ┃
// + 　　┃　　　　　 ┃
// + 　　┃　　┻　　　┃
// + 　　┃　　　　　 ┃
// + 　　┗━┓　　　┏━┛　Code is far away from bug with the animal protecting
// + 　　　 ┃　　　┃    神兽保佑,代码无bug
// + 　　　　┃　　　┃
// +　 　　　┃　　　┗━━━┓
// + 　　　　┃　　　　　　┣┓
// + 　　　　┃　　　　　　┏┛
// + 　　　　┗┓┓┏━┳┓┏┛
// + 　　　　 ┃┫┫ ┃┫┫
// + 　　　　 ┗┻┛ ┗┻┛
// +
// + ━━━━━━感觉萌萌哒━━━━━━
// +----------------------------------------------------------------------
namespace longzy;

class video {
    private $stream = '';
    private $buffer = 102400;
    private $start = -1;
    private $end = -1;
    private $size = 0;

    public function __construct($filePath='') {
        $this->path = $filePath;
    }

    //打开文件流
    private function open() {
        if (!($this->stream = fopen($this->path, 'rb'))) {
            return ['code' => '400', 'msg' => '无法解析视频流'];
        }
    }

    //设置header头
    private function setHeader() {
        ob_get_clean();
        header("Content-Type: video/mp4");
        header("Cache-Control: max-age=2592000, public");
        header("Expires: " . gmdate('D, d M Y H:i:s', time() + 2592000) . ' GMT');
        header("Last-Modified: " . gmdate('D, d M Y H:i:s', @filemtime($this->path)) . ' GMT');
        $this->start = 0;
        $this->size = filesize($this->path);
        $this->end = $this->size - 1;
        header("Accept-Ranges: 0-" . $this->end);

        if (isset($_SERVER['HTTP_RANGE'])) {
            $c_end = $this->end;
            list(, $range) = explode('=', $_SERVER['HTTP_RANGE'], 2);
            if (strpos($range, ',') !== false) {
                header('HTTP/1.1 416 Requested Range Not Satisfiable');
                header("Content-Range: bytes $this->start-$this->end/$this->size");
                exit;
            }
            if ($range == '-') {
                $c_start = $this->size - substr($range, 1);
            } else {
                $range = explode('-', $range);
                $c_start = $range[0];

                $c_end = (isset($range[1]) && is_numeric($range[1])) ? $range[1] : $c_end;
            }
            $c_end = ($c_end > $this->end) ? $this->end : $c_end;
            if ($c_start > $c_end || $c_start > $this->size - 1 || $c_end >= $this->size) {
                header('HTTP/1.1 416 Requested Range Not Satisfiable');
                header("Content-Range: bytes $this->start-$this->end/$this->size");
                exit;
            }
            $this->start = $c_start;
            $this->end = $c_end;
            $length = $this->end - $this->start + 1;
            fseek($this->stream, $this->start);
            header('HTTP/1.1 206 Partial Content');
            header("Content-Length: " . $length);
            header("Content-Range: bytes $this->start-$this->end/" . $this->size);
        } else {
            header("Content-Length: " . $this->size);
        }
    }

    //关闭文件流
    private function end() {
        fclose($this->stream);
        exit;
    }

    //执行计算范围的流式处理
    private function stream() {
        $i = $this->start;
        set_time_limit(0);
        while (!feof($this->stream) && $i <= $this->end) {
            $bytesToRead = $this->buffer;
            if (($i + $bytesToRead) > $this->end) {
                $bytesToRead = $this->end - $i + 1;
            }
            $data = fread($this->stream, $bytesToRead);
            echo $data;
            flush();
            $i += $bytesToRead;
        }
    }

    //开始处理
    public function start() {
        $this->open();
        $this->setHeader();
        $this->stream();
        $this->end();
    }
}
